The Functional Neuroanatomy of the Human Physiological Stress Response

Stress is common in daily life and is associated with adverse health outcomes. This proposal will study how a physiological stress (low blood sugar), a stress often experienced by people with diabetes, affects connections in the brain. The investigators will focus on brain connections that are involved in autonomic control of cardiovascular function, and determine both how these brain connections are altered by low blood sugar and how these alterations associate with changes in pain perception and cardiovascular control. In this study, the investigators introduce a novel mechanistic, integrative approach to the assessment of the response to and recovery from a specific physiologic stressor - insulin-induced hypoglycemia. The overall hypothesis is that a hypoglycemic stress will alter autonomic brain networks, and will affect clinically relevant physiological outcomes (cardiovascular autonomic function); and that the rate and extent of recovery of these brain networks will provide a measure of resilience. In combination, this approach will allow the investigators for the first time to define the magnitude of the effect of stress exposure on neural circuitry and on clinically relevant stress-related physiological outcomes (cardiovascular autonomic function) and to define the recovery of brain circuitry and these related physiological outcomes.